SAN FRANCISCO — In a victory for environmentalists, a federal judge ruled Tuesday that the Bush administration cannot change the standards commercial fisheries must meet before the tuna they catch can carry the “dolphin-safe” label.

U.S. District Judge Thelton Henderson found that Commerce Secretary Donald Evans not only failed to conduct the scientific research required to relax existing tuna-labeling laws, but engaged in “a pattern of delay and inattention” to build support for his position.

“The record is replete with evidence that the secretary was influenced by policy concerns unrelated to the best available scientific evidence,” Henderson wrote in a strongly worded 51-page opinion. “This court has never, in its 24 years, reviewed a record of agency action that contained such a compelling portrait of political meddling.”

What was proposedThe Commerce Department wanted to rewrite the 1990 law to allow tuna caught with nets to be labeled dolphin-safe if observers certified that no dolphins were killed or seriously injured in the process. Dolphins commonly swim with schools of tuna, and fisheries in Mexico and South America encircle the popular mammals with nets to hone in on their prey.

Tuesday’s ruling makes permanent an injunction Henderson issued last year that barred the Commerce Department from implementing the new rules while the case was pending.

“Judge Henderson’s ruling exposes the Bush administration’s deceit in ignoring its own scientists and caving into Mexican demands to allow dolphin-deadly tuna back into the U.S. with a phony label,” said Earth Island Institute director David Phillips, whose group was one of the plaintiffs in the suit against Evans.

A U.S. Justice Department spokesman said government attorneys would have to review the decision and consult with the Commerce Department before deciding whether to appeal.

Judge: No serious effortIn his opinion, Henderson condemned the process the Commerce Department used to conclude that dolphins would not be harmed if the labeling rules were relaxed.

The department never made a serious effort to determine if encircling methods of fishing increased dolphin mortality rates and erroneously concluded based on limited existing research that they didn’t pose a significant hazard, the judge said.

“Rather than supporting Defendants’ position, the record shows an agency that continued to drag its feet, exercised little diligence, and put obstacles in its own road,” Henderson wrote, adding that Evans’ “arbitrary and capricious” decision was prompted by international trade policy.